The invention relates generally to magnetic resonance (MR) imaging and, more particularly, to an apparatus and method for detecting and classifying atherosclerotic plaque hemorrhage.
When a substance such as human tissue is subjected to a uniform magnetic field (polarizing field B0), the individual magnetic moments of the spins in the tissue attempt to align with this polarizing field, but process about it in random order at their characteristic Larmor frequency. If the substance, or tissue, is subjected to a magnetic field (excitation field B1) which is in the x-y plane and which is near the Larmor frequency, the net aligned moment, or “longitudinal magnetization”, MZ, may be rotated, or “tipped”, into the x-y plane to produce a net transverse magnetic moment Mt. A signal is emitted by the excited spins after the excitation signal B1 is terminated and this signal may be received and processed to form an image.
When utilizing these signals to produce images, magnetic field gradients (Gx, Gy, and Gz) are employed. Typically, the region to be imaged is scanned by a sequence of measurement cycles in which these gradients vary according to the particular localization method being used. The resulting set of received NMR signals are digitized and processed to reconstruct the image using one of many well known reconstruction techniques.
Carotid plaque hemorrhage has been associated with increased plaque progression and increased risk of future stroke/transient ischemic attacks. Detection, identification, and classification of atherosclerotic plaque hemorrhage may allow a treatment plan to be developed for a patient having an atherosclerotic plaque hemorrhage such that negative risks associated therewith may be minimized.
It would therefore be desirable to have a system and method capable of detecting and classifying atherosclerotic plaque hemorrhage.